* feat(core): implement PIP-0001 database connection timeout recovery
- Add DbOperationBudget struct for unified execution budget model
- Add deadpool create/recycle timeout for PostgreSQL pools
- Add checkout_postgres_client helper replacing 14 bare pool.get() calls
with timeout + cancel token support
- Fix PostgreSQL TLS cancel: rebuild TLS connector from stored context,
fallback to NoTls on failure
- Add timeout to MySQL kill_query and kill_query_with_opts (5s)
- Extend is_connection_error to match deadpool pool timeout messages
- Unify keepalive default to 30s (was 60s Rust / 0s frontend mismatch)
- Inject PostgreSQL TCP keepalive params (idle=30s, interval=10s, retries=3)
- Inject MySQL tcp_keepalive=30s in OptsBuilder
- Make MySQL inactive_connection_ttl configurable from idle_timeout_secs
- Add stage-based structured logging for pool.checkout/health.check/cancel
- Store PostgresCancelContext in AppState for TLS cancel reconstruction
- Clean up cancel contexts on pool removal/drain
- Add unit tests for DbOperationBudget and pool timeout error detection
* fix(core): align timeout recovery with PIP-0001
* fix(core): handle timeout recovery review issues
* fix(core): complete connection timeout recovery
* fix(core): fall back postgres cancel connector build
* refactor: revert comment translations to English in connection.rs and query.rs
- Revert DbOperationBudget doc comments to English (query.rs)
- Revert PostgresCancelContext and TLS cancel comments to English (connection.rs)
- Keep Chinese error-matching strings in is_connection_error unchanged
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Co-authored-by: onceMisery <onceMisery@users.noreply.github.com>
When the LLM calls `list_tables` tool without a `schema` parameter, the
backend receives an empty string. This caused PostgreSQL and MySQL
metadata queries to return no results because:
- PostgreSQL: `WHERE n.nspname = ''` matches nothing
- MySQL: `WHERE TABLE_SCHEMA = ''` matches nothing
Fix by falling back to sensible defaults:
- PostgreSQL `list_tables`/`get_columns`: empty schema → "public"
- MySQL `list_tables`: empty schema → database name (MySQL schema == database)
t8y2